Polyurethane (PU) exhibits excellent chemical and mechanical properties because of which it is widely used for coating various materials. PU when mixed with Carbon Nanotubes (CNTs) exhibits even better properties, and accordingly a lot of methods have been developed for preparing Polyurethane-Carbon Nanotube (PU-CNT) composites.
The properties exhibited by the PU-CNT composites vary depending on the method used for preparing them. For example, a PU-CNT composite prepared using an extrusion process exhibits superior tensile strength and elongation at break. Similarly, a PU-CNT composite prepared using a solvent casting method provides a softer and more ductile PU. There are numerous such methods known in the art for preparing PU-CNT composites for use in different applications, wherein the method used for preparing the PU-CNT composites depends on the properties required in the corresponding application. For example, a PU-CNT composite prepared using a direct method of spinning can be used for electromagnetic interference shielding.
There are however limited methods for preparing PU-CNT based coating compositions. Further, the PU-CNT composites prepared using such methods exhibit only a few of the desired properties such as, but not limited to, superior impedance and mechanical properties. However, coating compositions are required to have various superior properties in combination.
In view of the above, there is a need for an improved method for preparing PU-CNT based coating compositions.